The spinal cord contains neural networks which can produce coordinated movements when properly stimulated. Our laboratory has developed the technique of electrical stimulation of spinal cord to elicit locomotor movements of the limbs of a turtle. When there is a spinal cord injury, such as total transection of the cord, this technique reveals that the spinal cord caudad to the transection can produce a normal locomotor movement. The electrical stimulation is serving as a neural prosthesis. The project research will continue our work with stimulation of the spinal cord of the turtle with the examination of neurons within the locomotor pattern generator of the spinal cord. We will study neurons within the pelvic enlargement of the spinal cord to determine how a hindlimb is controlled during locomotion. We will characterize neurons which serve to coordinate interlimb phase during locomotion. We will test the ability of chemical agents, e.g. excitatory amino acids, to produce a locomotor rhythm in the injured spinal cord. Our objctives are to elucidate the basic properties of spinal cord in a limbed vertebrate. It is known that there are many properties of spinal cord which are shared by both quadruped vertebrates and man. It is possible that the techniques developed for studies of locomotion in a reptile will have relevance to the clinical assistance of spinal cord injury in man.